As is known, cargo drops by parachute from aircraft have been extensively employed in military operations and disaster relief situations. In the usual parachute cargo delivery system, loaded platforms are guided for movement along the longitudinal axis of the aircraft between parallel rails secured to the aircraft floor. They can be pulled backwardly out of a rear cargo receiving and delivery opening by means of a parachute. Desirably, such cargo planes must also be capable of discharging cargo onto the ground as the aircraft accelerates over the ground surface.
In certain prior art aerial cargo delivery systems of this type, one of the two restraint rails which guide the cargo pallets are provided with aerial delivery system locks (i.e., those which permit only aft movement of a pallet under the force exerted by a parachute). The logistic locks (i.e., those which prevent both forward and aft movement during normal flight conditions) are carried on the other rail. In the aerial delivery mode, the logistic locks on the left rail, for example, are all disengaged while the aerial delivery locks on the right rail provide all forward and aft restraint. If it is necessary to return to the logistically locked position, the locks on the left rail must be manually reengaged. However, the pallets may shift slightly while the logistic locks are disengaged, resulting in a skewed condition of the pallets on the rails. This makes reengagement by the logistic locks very difficult due to slot misalignment. Furthermore, prior art systems wherein locks are deployed on both rails are heavy, complex and generally unreliable.